Potential therapeutic of olive oil industry by-products in skin health: a review

Olea europaea L. is one of the most important fruit trees in the Mediterranean countries due to its products, olive oil and table olives. However, the olive oil extraction industry produces large amounts of by-products, such as olive pomace, leaves and olive mill wastewater, which are considered harmful to the environment, having negative impacts on soil, aquatic and air ecosystems. The olive oil industry by-products are a major ecological issue mainly due to their phenolic components, such as oleuropein, hydroxytyrosol and tyrosol. However, olive oil industry by-products can be recovered, treated and studied for their health-promoting properties, holding great potential for the cosmetic and pharmaceutical industries. Furthermore, the recovery and treatment processes contribute to an efficient waste management and sustainability of the olive oil industry, leading to important economic benefits. The phenolic compounds extracted and obtained from these by-products present numerous health properties and can be used as antioxidant, photoprotector, anti-inflammatory and/or antimicrobial agents in wellness and therapeutics of the skin. This review highlights issues related to olive oil industry by-products and then proceeds to discuss how their beneficial biological activities make them reusable, particularly their high positive impact in treating skin disorders.